To guarantee the quality of the die-pressed parts and to cool, clean and lubricate the forging dies required for shaping, it is necessary to blow the surfaces of the molds free of forging scales, and to lubricate and cool them sufficiently. This is done in various ways. In hand-operated drop-forging presses, the molds are lubricated and blown out with a hand spraygun by the operator. The same can be done using a stationary nozzle system mounted in the upper and lower mold areas. It is also known to use pneumatically, electrically or hydraulically driven spraying arms located at either the rear or the side depending on the design of the individual drop forging press. Using hand operated presses, the operator actuates an appropriate switch at the end of the respective forging process and then carries out the blowing and spraying process.
When a drop-forging press has an automatic workpiece transport, the workpieces are transported from one work station to another within the tool area by using walking beams. There is no time gap between the working on various parts as when the forging operation is effected by hand. The workpiece transport is carried out continually within the mold area of the forging press. Using this type of transport system, the forging operation is carried out with each second forging station being occupied. That is, during the automatic procedure of the forging system, only each second forming station is occupied by a workpiece.
In this particular prior art arrangement, the blowing and spraying of the dies is carried out only when the dies are free of the workpiece and no pressing stroke is being effected. The time available for blowing and spraying the dies is extremely short and can be less than one second depending upon the number of strokes carried out by the automatic walking beam. When using electrically, pneumatically or hydraulically controlled spraying arms, such arms can be guided into the mold area only when the plunger of the forging press has stopped in its upper dead center. Thus, a significant portion of the already short length of time available for blowing and spraying is lost during the control and monitoring times of the forging press and transport operation.